Flexible spiral wound conduits are well known for carrying and protecting electrical conductors, sometimes referred to as “goosenecks”. Such flexible conduits have recently become miniaturized and used to carry internal wiring for communications purposes such as microphone holders. Also well known are telescoping coaxially sliding tubes used as conduits to extend or contract the conduit. These are used with swivel table lamps and also to hold microphones. Each of these two different types of conduits has utility for specific applications. For example, spiral wound flexible casings may be bent universally in different directions and hold the bent position, but are non-extendible. On the other hand, telescoping tubes will extend and contract in a single direction, but are not bendable or flexible, and require universal joints or pivots at their ends to change their orientation.
U.S. Pat. No. 5,065,299 issued Nov. 12, 1991 to Cohen discloses a power extendible lamp, wherein short telescopic sections of non-circular cross section appear to give limited flexibility to a lamp holder. Limited curvature is apparently achieved by utilizing many very short telescopic sections.
U.S. Pat. No. 3,324,254 issued Jun. 6, 1967 to Shaw et al. discloses a microphone holder with a rigid telescoping section containing microphone wires which collapse into the space between the ends of the telescoping tubes when the unit is contracted. A jam nut is required to hold a desired position, and provision for vibration reduction is also added. A pivot pin and a swivel mounting allow for movement of the microphone in different directions.
U.S. Pat. No. 2,209,912 issued Jul. 30, 1940 to Deems illustrates a telescoping underground protective conduit for armored electrical cable, which is helically wound inside the inner telescoping tube to permit raising the upper end of the assembly.
There is a need for a flexible extendible conduit which will accommodate a number of conductors, which allows full freedom of direction at one or both ends of the conduit as well as the ability to extend and contract in length. All of this should be suitable for ease of manufacture in miniaturized form, so that it could be used for applications such as microphone holders, small lamps and the like. In addition, it would be desirable to lock the telescoping section in a desired place without the need for a jam nut which is commonly employed today in microphone holders. Also there is a need for an extendible flexible conduit which reduces vibration or shocks due to impact.
Accordingly, one object of the present invention is to provide an improved extendible flexible electrical conduit with conductors therein.
Another object is to provide such an extendible flexible electrical conduit with means to lock the extendible section in place.
Another object is to provide such an extendible flexible electrical conduit which reduces shocks and vibration along the conduit.